An organic farm that drew national headlines when it began growing vegetables on a Long Island City roof has been sued by a national farmers advocacy group over its name.

The National Grange of the Order of Patrons of Husbandry claims the Brooklyn Grange cannot use the word “grange” in its title because it has a trademark on the word.

The Washington, D.C.-based organization filed a lawsuit on Nov. 1 in Brooklyn federal court in the U.S. District Court, Eastern District of New York to stop the farm from using the name. A court hearing is scheduled for Wednesday.

“We needed to take action to preserve our name,” said National Grange spokeswoman Amanda Brozana, whose group sent a letter to the rooftop farm more than a year ago. “It’s something we’ve had since the late 1800s.”

The National Grange has more than 2,500 chapters, including one in Connecticut known as the Brooklyn Grange since 1886, she said.

“Preserving the name ‘grange’ is really not about being stingy with a word,” said Brozana, who added local chapters do everything from donating dictionaries to local children to building playgrounds. “It’s our true identity.”

The group holds a trademark on “grange” for anything from farmers markets and catering to jewelry and clothing, she said. But it does license it for annual fees ranging from $100 to $1,000.

Trademark attorney Stephen Baker, who has no affiliation with the case, said it is fairly common for companies and organizations to obtain trademarks in the fields that they do business in.

The word “grange” means a farm or a “farmhouse with outbuildings,” according to Merriam-Webster.

But “you can’t use a trademark if it’s likely to cause confusion with another company that uses the same or a confusingly similar trademark,” said Baker, of the Manhattan and New Jersey firm Baker and Rannells, PA.

James Bikoff, the lawyer who represents the National Grange, said his client has communicated with the Brooklyn Grange, but they have not reached a resolution.

“We wouldn’t have filed the suit if we didn’t feel we were in the right,” Bikoff said.

The Brooklyn Grange, which planted its first crop in May 2010, did not respond to questions on whether it plans to fight the case in court.

“We respect the work of the National Grange and their long history of supporting small farms,” the farm said in a statement. “We hope we can come to a resolution of this matter.”